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Current & Breaking News | National & World UpdatesMon, 19 Mar 2018 14:53:54 +0000enhourly1http://wordpress.com/http://0.gravatar.com/blavatar/2cee445ea71a179ffd35ea91cf154905?s=96&d=http%3A%2F%2Fs2.wp.com%2Fi%2Fbuttonw-com.pngScience – TIMEhttp://time.com
This is an XML content feed. It is intended to be viewed in a newsreader or syndicated to another site, subject to copyright and fair use.Donald Trump Said America Is Going to Mars. Here’s Why That Won’t Happen Any Time Soonhttp://feedproxy.google.com/~r/time/scienceandhealth/~3/3_qo4is6xvk/
Fri, 16 Mar 2018 20:13:22 +0000http://time.com/?p=5202056

History has no record of the first drafts of the speeches President Kennedy delivered in 1961 and 1962, when he set America on a path to space. Still, it’s a safe bet they didn’t include the lines: “Space is a warfighting domain. We may have a Space Force. Develop another one. Space Force.”

He also probably didn’t consider saying, “You see what’s happening? You see the rockets going up left and right… Very soon we are going to the moon.” And he almost surely didn’t think about saying, “You wouldn’t have been going to the moon if my opponent won, that I can tell you. ”

President Kennedy, however, wasn’t President Trump, and the current President said precisely those things in a speech at the Marine Corps Air Station in Miramar, Calif., on March 13 — only instead of the moon, he promised Mars.

Article IV of the treaty explicitly forbids nuclear or other weapons of mass destruction anywhere in space, as well as any military activity of any kind on the moon or other worlds.

Even if Trump kept the space weaponry conventional, there’s a risk of nuclear escalation back on Earth. In 1983, President Reagan proposed his Strategic Defense Initiative (SDI), an array of non-nuclear, space-based defensive weapons to protect the U.S. from a first-strike attack by the Soviet Union. Moscow, however, saw a good defense as at least a prelude to offense and warned that the SDI violated the existing Anti-Ballistic Missile (ABM) pact and Strategic Arms Limitation Treaty (SALT) — both of which regulated nukes. Tear up ABM and SALT, and you’re off to the arms races.

Star Wars was not the first time the U.S. considered militarizing space. The idea initially got traction in 1963, when the Air Force announced its plans for a Manned Orbiting Laboratory, which was actually not a laboratory at all, but instead a single-module space station for astronaut-spies. That project too had its run, burned through $1.5 billion in 1960s dollars, and was scrapped in 1969. And that one too never worked out its engineering bugs, except for the toilets — really — which later flew on the Skylab space station.

This time, even the military isn’t buying what Trump is selling. In July of last year, when Congress actually considered funding a space force, Defense Secretary Jim Mattis shot it down. “At a time when we are trying to integrate the Department’s joint war-fighting functions, I do not wish to add a separate service that would likely present a narrower and even parochial approach to space operations,” he wrote in a letter to a Congressional Republican who also opposed the idea. Mattis appears no more favorably inclined today, and the chilly silence you heard from the Pentagon following Trump’s speech shows that.

Ever since the first moon landing, in 1969, the rule for Mars has always been that we’re going there, we just never actually get there. First, the target date was 1975, then 2019 — chosen because it will be the fiftieth anniversary of that moon landing. Now it’s 2035 or so. Elon Musk, the head of SpaceX, has claimed he could get there by 2024.

It’s Musk’s accomplishments that seem to be behind Trump’s current Red Planet Fever. At a March 8 cabinet meeting, the President was still swooning over the Feb. 6 launch of SpaceX’s Falcon Heavy rocket — particularly the safe landing of two of its three spent boosters. (The third one crashed.) But Musk himself has walked back his 2024 promise and gotten a good deal more realistic about the challenges a Mars mission poses. “It’s difficult, dangerous, [and there is a] good chance you will die,” he said at a South by Southwest talk on March 11.

Trump has much more control over NASA’s own Mars push, but he’s not really exercising it. NASA’s annual budget comes in just north of $19 billion, which represents about 0.4% of the federal budget. Back in the Apollo days, it was 4%. That lean funding has meant go-slow progress on the principal hardware needed for a Mars mission — the Orion spacecraft and the heavy-lift SLS rocket — both of which have been in development since 2004. The earliest launch of even an uncrewed test version will not likely occur until 2020. If Trump wants to speed things up, he could work with Congress to open the money spigot much wider. He hasn’t.

Finally, there is the matter of Trump’s swipe at Hillary Clinton, in which he suggested that she was indifferent to a Mars mission. But as is often the case, Trump seems to have made this up on the fly. In an online science debate during the election in which the presidential candidates submitted written answers to questions, Clinton wrote: “Today, thanks to a series of successful American robotic explorers, we know more about the Red Planet than ever before. A goal of my administration will be to expand this knowledge even further and advance our ability to make human exploration of Mars a reality.” She restated that commitment in a similar forum with Space News magazine.

Trump did not mention Mars on either occasion, but he did write that a strong STEM program in schools will help “bring millions of jobs and trillions of dollars in investment to this country.” There was no real-time moderator to press him on the “trillions.”

The current president may or may not be learning an immutable truth that previous presidents have learned, which is that it’s extremely easy to get drunk on space, but it’s extremely hard to turn that intoxication into a working national space policy. The job takes discipline, vision, patience, an ability to work closely with Congress and a real understanding of the relevant science. A few of those previous presidents exhibited those qualities. If the current one wants to get anywhere near Mars, he will have to do the same.

During the fall of my sophomore year at Harvard, a group of my fellow physics majors were excitedly discussing a rumor they’d just heard: Stephen Hawking was coming to give the prestigious Loeb Lectures. I played along with their excitement, but truth be told, I didn’t know who Stephen Hawking was. This was the early 1980s, well before A Brief History of Time, so to all but the most physics-savvy of people, Hawking had yet to become Hawking. The rumor was true, and a few weeks later the physics-savvy crowd turned out in force, packing the largest hall to hear Hawking discuss relativity and the origin of the universe.

Although his movements had been reduced to flicking a finger or squinting an eye, Hawking could still speak — a soft, monotone murmur that was barely audible. One of Hawking’s graduate students, trained to decipher his speech, sat inches from the wheelchair, attentively listening and relaying Hawking’s remarks to an audience that hung on every word. The reduced pace allowed me to follow a lecture that otherwise would have left me baffled, making the experience all the more remarkable. I was riding to the edge of space and time on a mind soaring free of a body that had been mandated to sit as still as stone.

As the world would come to know, Hawking suffered from amyotrophic lateral sclerosis, a disease that ravages the neurons controlling voluntary muscle movement, but leaves cognitive functioning intact. By shifting from the tactile tools of a typical theoretical physicist — pen, paper, chalkboards, computers — to diagrams and imagery he could manipulate solely with the mind’s eye, Hawking was able to continue his research and, in time, see further than anyone previously had. Among much else, that vision would illuminate the darkness of black holes.

Hawking didn’t discover black holes. But he sparked a revolution, still ongoing, in our understanding of them. In the early decades of the 20th century, we learned from Einstein’s theory of gravity, known as the general theory of relativity, that if you cram enough matter into a small enough region, the gravitational pull will be so strong that nothing can escape its forceful grip. Included in that “nothing” is light, and so the gravity-infused mass will go dark — it will fade to black. In the early 1970s, Hawking updated this conclusion by including quantum mechanics, the hard-won mathematical description of the behavior of particles like electrons and photons, developed in the first half of the 20th century. What Hawking found was so surprising that at first even he didn’t believe it. Through quantum processes, particles can leak through the surface of a black hole, creating an outward streaming swarm causing a black hole to glow — or even explode. Black holes, in other words, are not fully black. They radiate. Although such “Hawking radiation” has yet to be observed (for typical black holes, the effect is minuscule) there is now universal consensus that Hawking’s analysis is correct.

The result transcends black holes. It reveals strange properties of space, time and gravity in a quantum universe that have thrilled, fascinated and frustrated physicists for more than 40 years. One stunning outgrowth of Hawking’s insight, at the forefront of current thinking, is that the three-dimensional reality we inhabit may be akin to a hologram — we may be a three-dimensional projection of comings and goings that take place on a thin two-dimensional surface that surrounds us. Called the holographic principle, it’s one of the strangest ideas of modern physics, and one that emerged from physicists carefully thinking about Hawking’s radiation and its implications for the information carried by anything that falls over a black hole’s edge. Many now believe that the holographic insight is essential to realizing Einstein’s dream of a unified theory of all of nature’s forces.

Some years back, Hawking was the honored guest at the World Science Festival’s annual gala in New York. As we accompanied Stephen through the throngs of invited guests and swarms of press and photographers — all pushing in, straining to catch a glimpse — it became beyond intense. For brief moments, it felt atavistic. Yet, Stephen seemed to take it all in stride. I remembering wondering: Is he off in another world, undertaking some mental calculation that lets him rise above the tumult? Is he parking his mind near the edge of a black hole, reducing the time he’ll experience before it’s safe to come back to Earth? I will never know. But as I think about it now, I like to imagine he was mulling over a remark he’d made some years earlier, in which he reflected on our bestial past and captured in the simplest and starkest terms what it means to be human: “We are just an advanced breed of monkeys on a minor planet of a very average star. But we can understand the Universe. That makes us something very special.” And how special for us to have been on this minor planet while this major mind rewrote the rules of reality.

]]>Theoretical physicist Stephen Hawking poses for a picture ahead of a gala screening of the documentary 'Hawking', a film about the scientist's life.http://time.com/5201750/stephen-hawking-brian-greene-obituary/Remembering Stephen Hawking’s Greatest Scientific Accomplishment — and My Famous Bet Against Himhttp://feedproxy.google.com/~r/time/scienceandhealth/~3/Jh5fJOG1MOw/
Thu, 15 Mar 2018 16:58:09 +0000http://time.com/?p=5201371

Stephen studied time from the perspective of Einstein’s theory of gravitation, the general theory of relativity. One of his early achievements was proving that time had a beginning — that the laws of physics as we now understand them must have broken down very early in the history of the universe, at the Big Bang. Stephen also greatly advanced our understanding of black holes, where gravitational forces are so strong that time comes to an end. He argued forcefully that travel backward in time is disallowed by the laws of physics, which (as he put it) “makes the world safe for historians.” No one understood time better than Stephen Hawking.

Stephen’s greatest scientific achievement was a discovery about black holes in 1974 that shook the world of physics. According to Einstein’s theory, nothing — including light — can escape from inside a black hole. That’s why it’s black. But Stephen found that black holes are not really completely black. Instead, due to the subtle consequences of quantum physics, they emit what we now call Hawking radiation. That insight ignited a controversy that still rages 44 years later, regarding what happens to information that falls into a black hole. If I drop my highly confidential diary into a black hole, will it be lost forever from the universe? Or will it emerge from the black hole hidden in the Hawking radiation, highly scrambled but decipherable in principle? We still don’t know the answer for sure, but Hawking’s breakthrough laid the foundation for much of the progress we’ve made on the greatest challenge facing fundamental physics: understanding how gravitational physics and quantum physics fit together.

While his scientific accomplishments alone would suffice to ensure an enduring legacy, Stephen Hawking also became one of the world’s most successful popularizers of science. Stephen firmly believed that the quest for a complete theory of the universe should be accessible to everyone, at least in broad principle, not just to a few specialists. That conviction drove him to write A Brief History of Time. While other scientists write books for lay readers, only Stephen seemed to earn tenure on the New York Times bestseller list, thanks in part to that ingenious title. The book sold over 10 million copies and was translated into dozens of languages. Its extraordinary success led to more books, including a series for children Stephen co-authored with his daughter Lucy.

And I haven’t even mentioned yet what made Stephen Hawking the most famous scientist in the world — he achieved scientific greatness despite a severe physical disability, all while displaying a zest for life and buoyant sense of humor that seemed miraculous under the circumstances. People rooted for Stephen, and he appreciated having millions of fans.

Stephen was fun to be with. I sensed when we first met that he would enjoy being treated irreverently. So in the middle of a scientific discussion I could interject, “And what makes you so sure of that, Mr. Know-It-All?” After a beat Stephen would respond with a glint in his eye: “Wanna bet?”

With our friend Kip Thorne, we made some of those bets “official,” and we were all taken aback by how much attention they received. Stephen conceded our most famous bet (regarding whether black holes destroy information) in 2004, before an audience in Dublin of 700 scientists and at least 50 reporters from print and electronic media. To pay off, he presented me with Total Baseball: The Ultimate Baseball Encyclopedia. You can’t buy one of those in Ireland, so Stephen’s assistant had arranged to have it shipped overnight just in time. Not knowing what else to do, I held the book over my head as though I had just won the Wimbledon final, while a million flashbulbs were popping (it seemed like a million, anyway). One of those pictures wound up in Time.

We made bets for fun, but the scientific issues in question, founded on some of Stephen’s most far-reaching contributions, are ones many physicists passionately care about. Combining extraordinary depth of thought with an irrepressible sense of play, that’s what I’ll remember best about Stephen Hawking.

]]>breakthrough-starshot-initiative-stephen-hawkinghttp://time.com/5201371/stephen-hawking-john-preskill-obituary/Scott Kelly Spent a Year in Space and Now His DNA Is Different From His Identical Twin’shttp://feedproxy.google.com/~r/time/scienceandhealth/~3/UwpiHb-0CR0/
Thu, 15 Mar 2018 15:39:21 +0000http://time.com/?p=5201064

Scientists found that Scott Kelly, who set the record for most consecutive days spent in orbit, underwent an “unexpected” genetic change. Post-flight, NASA investigators found “hundreds of unique mutations.” Some involved the circulation of so-called cell-free DNA in the blood. Others involved changes in the epigenome — a sort of genetic control system that determines how genes are expressed. Still others involved a lengthening of telomeres, the caps on the ends of chromosomes that help regulate the aging process.

About 93% of the changes were temporary, with Kelly’s genetic profile returning to normal comparatively quickly after his return to Earth; in the case of the telomeres, the lengthening vanished within 48 hours. But about 7% of the changes have remained in the two years since he returned to Earth. Those involved genes relate to Kelly’s “immune system, DNA repair, bone formation networks, hypoxia, and hypercapnia”, the study says.

The results form part of NASA’s “Twins Study,” as Kelly’s genes were compared to his identical twin brother Mark, who remained on Earth as a control factor in the experiment.

Scott Kelly recently took to Twitter to marvel at the report himself. He joked that it’s “good news” because he no longer has to call Mark his identical twin.

What? My DNA changed by 7%! Who knew? I just learned about it in this article. This could be good news! I no longer have to call @ShuttleCDRKelly my identical twin brother anymore. https://t.co/6idMFtu7l5

NASA, though, made clear nothing has changed in the Kellys’ genetic relationship.

“Mark and Scott Kelly are still identical twins,” the agency said in a statement. “Scott’s DNA did not fundamentally change. What researchers did observe are changes in gene expression, which is how your body reacts to your environment. This likely is within the range for humans under stress, such as mountain climbing or SCUBA diving. The change related to only 7 percent of the gene expression that changed during spaceflight that had not returned to preflight after six months on Earth. This change of gene expression is very minimal. We are at the beginning of our understanding of how space flight affects the molecular level of the human body. NASA and the other researchers collaborating on these studies expect to announce more comprehensive results on the twins studies this summer.”

The new findings matter for reasons that go well beyond the Kelly brothers’ genes and overall health. A mission to Mars will take up to three years, depending on how long astronauts remain on the Red Planet. Only when we fully understand the punishment the body takes during long-duration space flight will that be a mission we can safely attempt.

Drinking from a plastic water bottle likely means ingesting microplastic particles, a new study claims, prompting fresh concerns — and calls for scientific research — on the possible health implications of widespread plastics pollution.

A study carried out on more than 250 water bottles sourced from 11 brands in nine different countries revealed that Microplastic contamination was nearly universal, found in more than 90% of the samples.

The study, by journalism organization Orb Media and researchers at the State University of New York at Fredonia, found an average of 10.4 microplastic particles about the width of a human hair per liter. That’s about twice the level of contamination discovered in the group’s earlier study on the ubiquitous plastic contamination in tap water across the globe, with the highest rate found in the U.S.

Previous studies have found that a large portion of the microplastic particles found in our oceans, lakes and rivers, as well as in fish stomachs, can be traced back to the washing of synthetic clothes.

In the case of bottled water, Orb’s new study indicated contamination was partly the result of plastic packaging, and partly the fault of the bottling process. The survey included brands like Aquafina, Dasani, Evian, Nestlé and San Pellegrino.

It’s unclear what effect, if any, this consumption of tiny bits of plastics has on human health. As much as 90% of ingested plastic could pass through a human body, but some of it may end up lodged in the gut, or traveling through the lymphatic system, according to research by the European Food Safety Authority.

For years, the best way to establish my place in the physics world with people outside of physics was to tell about the time Stephen Hawking saved me a seat. I was at a conference in the early 2000s and had done some work that he was following. When I showed up late to a dinner, a physicist pulled me aside to be seated next to Stephen’s place. On this fortunate evening, I got to know him a bit better — hearing his thoughts on science, his jokes and his observations. But to tell the truth, probably the most fascinating part for me was simply understanding how he functioned and communicated despite all the obstacles. He would painstakingly work through his letters and words (happily I could see my name among them) to construct sentences and when they were complete everyone paused to engage. The man had a good time — and clearly it was a decision on his part to do so.

In our incredible, challenging-to-explain universe, it seems almost inevitable that it was an incredible, challenging-to-explain person who made it more comprehensible — both to the scientific community and to the public. Whether people agreed or disagreed with his latest pronouncements on physics, on AI or the fate of the Earth, one thing that everyone agrees on is how impressive were Stephen Hawking and his accomplishments, never mind his very survival.

The story is well known. A promising physicist who in his early years gets a diagnosis that many interpret as an imminent death sentence — ALS — a disease that a doctor friend of mine describes as one of the worst anyone can suffer. Everything stops working except your brain, which goes on as sharply (or fuzzily for some) as ever. Hawking showed us why this disease can be far from the worst. A functioning brain coupled with what little of his body survived — less and less over time — was enough for this formidable individual to have a life far more active than that of most able-bodied individuals and a life of the mind that exceeded others’ by many multiples.

Stephen Hawking came into the public eye primarily through his book A Brief History of Time, published in 1988. It never was quite clear what was responsible for the book’s oversized popularity — the wonderfully clever title, the material itself, the way it was written or the person in the wheelchair who explained things so well — but the fact is that millions of copies were sold and Stephen Hawking became synonymous with genius and physics research. He also became the conduit through which many people learned about advances in physics and became excited about them.

But Hawking wasn’t just the over- or undersized person (depending on how you look at it) who was familiar to viewers of The Simpsons, The Big Bang Theory, to attendees of his many lectures or to readers of his books. He was a major scientific figure whose contribution to our understanding — particularly of black holes — both advanced our understanding and laid bare the mysteries that forty years later are still daunting. They are questions related to deep and significant questions such as where information goes and how causality survives in the process. If most people can’t begin to answer them, Hawking helped everyone at least approach them and with his bets, pronouncements and research, lure them to greater achievements.

In addition, he is responsible for formal mathematical advances I can’t describe fully in this short space concerning singularities — where spacetime breaks down — and the wavefunction of the universe. He also played an important role in the physics community’s understanding of the fluctuations in density that give rise to the structure of the universe.

Hawking’s personal universe had a complexity of its own. He had two wives, three children, explored the world in ways most people don’t — going down a mine shaft, traveling in a submarine, visiting the south pole and going up into zero-gravity. He was clever, witty and had a zest for life, along with many of the more annoying features that physicists deservedly are reputed to have.

My chief concern about Hawking’s influence is that people will think you have to be so disadvantaged to participate fully in the life of the mind. Science is not part of a separate world; it is integrated fully into all our lives and is available for anyone to participate. His contributions should be an inspiration, not an excuse to turn away from the challenges of science. But with his many accomplishments, he certainly lays down the gauntlet.

Even near the end, Hawking kept pushing to add to his body of research. I got to know him when he did work on black holes, related to the geometries that Raman Sundrum and I had studied, and more recently when he worked on fundamental questions about black holes with another Harvard colleague.

There are many who worked more closely with Stephen than I, and all of them have nothing but admiration for him. To carry on despite the odds and to do work that would be widely recognized even without Hawking’s handicap is indeed a model for us all. His enjoyment of people and desire to be with them, to share his insights and fight for science will be missed. It is now up to us all to ensure that his legacy of inspiration, science communication and science itself thrive and survive.

A solar storm this week will heighten the Earth’s auroras, making the stunning northern lights visible to the northern-most parts of the United States.

Lasting from Wednesday through Thursday, the geomagnetic storm will also impact the Earth’s magnetosphere — or magnetic field, which is impacted by changing solar winds. That means the storm could cause minor “power grid fluctuations” and have small impacts on orbiting satellites, according to the Space Weather Prediction Center from the National Oceanic and Atmospheric Administration.

It appears this upcoming event will allow residents in U.S. to catch a rare glimpse of the northern lights. The center says residents in the northern tier of the U.S., including Michigan and Maine, may be able to see the auroras.

A G1 Watch is in effect for the 14 & 15 March, 2018 UTC-days. Enhancements in the solar wind due to the anticipated effects of a coronal hole high speed stream (CH HSS) are expected to cause the escalated geomagnetic responses. Visit https://t.co/dimAHi8BFd for the latest info. pic.twitter.com/doJIzMWaGe

According to a graph from the space center, it also appears states like North Dakota, South Dakota, Minnesota and Wisconsin could also see the lights as a result of the storm. In addition, the northern-most part of Ireland, Norway, and parts of Sweden and Finland can see the lights.

The minor storm is classified as G1, which is the lowest on the scale of intensity from the Space Weather Prediction Center. These kinds of storms occur about 2,000 times over 11 years, the center says, which amounts to more than 180 times per year. The highest level of this kind of storm is a G5, which would involve a “high frequency radio blackout” on the sunlit side of the world for several hours, according to the center. Those come once every 11 years. The largest of these storms come as a result of the release of plasma from the Sun’s corona, called coronal mass ejections, that arrive at Earth and disturb its magnetic fields.

Some people on the internet think Stephen Hawking couldn’t have calculated a better day to die.

The 76-year-old theoretical physicist, one of science’s most famous luminaries died on March 14, also known as National Pi Day — an annual day for scientists and mathematicians around the world to celebrate the value of pi that even includes deals on pizzas and actual pies. Suffice it to say that the noteworthy coincidence was not lost on the internet.

The date of Hawking’s death — 3/14 — is significant because 3.14 are the first three digits of pi, a bedrock of geometry. Specifically, it’s the ratio of a circle’s circumference to its diameter. Naturally, the fact that science’s big celebration overlapped with the day the life of the party left us is making people geek out about the details.

As soon as news spread that Hawking died early Wednesday morning in London, people were quick to to connect the dots.

ON #PiDay 2018, I join @Perimeter & the world in sadness & express condolences to family and colleagues as we say goodbye to Stephen Hawking. Just like Pi never ends, your amazing mind has left our planet an endless legacy which you kindly shared with #WRAwesome and the world! pic.twitter.com/dbUYfT1Ngt

Somber Pi Day today, with the passing of Stephen Hawking. His book “A Brief History of Time” is fantastic. (The first three chapters at least—after that I got totally lost and never came back.) Plus, great Simpsons cameo!https://t.co/s5DCBGWK5L via @youtube

“We have lost a truly beautiful mind, an astonishing scientist and the funniest man I have ever had the pleasure to meet,” Redmayne said in a statement provided to Deadline. “My love and thoughts are with his extraordinary family.”

Redmayne met Hawking just five days before he began shooting his Oscar-winning portrayal of the legendary physicist and bestselling author, who was diagnosed with ALS at age 21, but still went on to become one of the world’s best-known and most beloved scientific minds while battling the neurodegenerative disease for more than 50 years. Hawking later praised Redmayne’s turn in the film.

The author of A Brief History of Time, Hawking was a living legend in the field of cosmology. He was most famous for his studies on black holes and relativity, which revolutionized the way we see and study the universe. His work with Sir Roger Penrose on Einstein’s general theory of relativity showed that there was an implied beginning to space and time — the Big Bang — and an end, through black holes.

However, for all his fame and impact on theoretical physics, his field’s most famous award eluded Hawking throughout his life. So why did one of science’s most iconic pioneers never win a Nobel Prize in Physics?

Theoretical scientific discoveries have to be confirmed by observational data before there’s a possibility of winning a Nobel. And it’s somewhat difficult to observe a black hole.

It takes decades to build the scientific equipment to test theoretical discoveries; to put this into context, Einstein’s theory of gravitational waves in space, which he first proposed in the 1920s, was only recently proven in 2016.

One of Hawking’s most important finds was “Hawkings Radiation,” the theory that black holes are not completely black after all, but emit radiations that ultimately cause them to disappear. The issue is, the technology needed to observe this radiation will take years and cost millions before Hawking’s theory can ever be verified.

Hawking never won a Nobel, but as an ambassador for the sciences his influence was profound, as shown by the world leaders and celebrities who took to social media today to pay tribute. See a selection of tributes below.

The world has lost a beautiful mind and a brilliant scientist. RIP Stephen Hawking

His passing has left an intellectual vacuum in his wake. But it's not empty. Think of it as a kind of vacuum energy permeating the fabric of spacetime that defies measure. Stephen Hawking, RIP 1942-2018. pic.twitter.com/nAanMySqkt

Professor Stephen Hawking was an outstanding scientist and academic. His grit and tenacity inspired people all over the world. His demise is anguishing. Professor Hawking’s pioneering work made our world a better place. May his soul rest in peace.